Phot (ph)
CGS unit of illuminance: one lumen per square centimeter, exactly 10,000 lux.
What is a phot?
- Symbol
- ph
- Quantity
- Illumination
- Unit system
- CGS
- Definition
- CGS unit of illuminance: one lumen per square centimeter, exactly 10,000 lux.
- Exact
- Yes, the value is exact by definition
- Source
- NIST Special Publication 811 (2008), Appendix B.8
Common applications
An older CGS unit of illuminance, now found mainly in older physics and photometry texts.
Phot in other illumination units
- 1 ph = 10000 lxPhot to Lux converter
- 1 ph = 10 klxKilolux
- 1 ph = 10000000 mlxMillilux
- 1 ph = 929.0304 fcFoot-candle
Phot quick reference
| Phot | Lux | Foot-candle | Kilolux |
|---|---|---|---|
| 1 ph | = 10000 lx | = 929.0304 fc | = 10 klx |
| 10 ph | = 100000 lx | = 9290.304 fc | = 100 klx |
| 100 ph | = 1000000 lx | = 92903.04 fc | = 1000 klx |
| 1000 ph | = 10000000 lx | = 929030.4 fc | = 10000 klx |
Where the phot fits
The next smaller illumination unit is the kilolux (klx). 1 ph = 10 klx, and 1 klx = 0.1 ph.
Frequently asked questions
- How many lux are in one phot?
- One phot = 10000 lx (lux).
- How many foot-candles are in one phot?
- One phot = 929.0304 fc (foot-candles).
- How many kilolux are in one phot?
- One phot = 10 klx (kilolux).